AUTHOR=Petrone Salvatore , Ajello Marco , Marengo Nicola , Bozzaro Marco , Pesaresi Alessandro , Allevi Mario , Fiumefreddo Alessandro , Denegri Federica , Cogoni Maurizio , Garnero Andrea , Tartara Fulvio , Di Perna Giuseppe , Armocida Daniele , Pesce Alessandro , Frati Alessandro , Zenga Francesco , Garbossa Diego , Cofano Fabio 

TITLE=Clinical outcomes, MRI evaluation and predictive factors of indirect decompression with lateral transpsoas approach for lumbar interbody fusion: a multicenter experience

JOURNAL=Frontiers in Surgery

VOLUME=10

YEAR=2023

URL=https://www.frontiersin.org/journals/surgery/articles/10.3389/fsurg.2023.1158836

DOI=10.3389/fsurg.2023.1158836

ISSN=2296-875X

ABSTRACT=<sec><title>Introduction</title><p>Evaluating the effects of indirect decompression obtained through lateral lumbar interbody fusion (LLIF) by clinical improvements and radiological parameters on MRI scans. Identifying predictors of better decompression and clinical outcome.</p></sec><sec><title>Materials and methods</title><p>From 2016 to 2019, patients who underwent single- or double-level indirect decompression LLIF were consecutively reviewed. Radiological signs of indirect decompression were evaluated in preoperative and follow-up MRI studies and were subsequently correlated to clinical data, expressed as axial/radicular pain (VAS back/leg), index of disability (Oswestry Disability Index) and clinical severity of lumbar stenosis (Swiss Spinal Stenosis Questionnaire).</p></sec><sec><title>Results</title><p>72 patients were enrolled. The mean follow-up was 24 months. Differences in vertebral canal area (<italic>p</italic> &lt; 0.001), height of the foramina (<italic>p</italic> &lt; 0.001), thickness of the yellow ligament (<italic>p</italic> = 0.001) and anterior height of the interbody space (<italic>p</italic> = 0.02) were observed. Older age (<italic>p</italic> = 0.042), presence of spondylolisthesis (<italic>p</italic> = 0.042), presence of intra-articular facet effusion (<italic>p</italic> = 0.003) and posterior height of the implanted cage (<italic>p</italic> = 0.020) positively affected the increase of the canal area. Change in root canal area (<italic>p</italic> &lt; 0.001), height of the implanted cage (<italic>p</italic> = 0.020) and younger age (<italic>p</italic> = 0.035) were predictive factors of root pain relief, while increased vertebral canal area (<italic>p</italic> = 0.020) and height of the interbody fusion cage (<italic>p</italic> = 0.023) positively affected the severity of clinical stenosis.</p></sec><sec><title>Conclusions</title><p>LLIF indirect decompression showed both clinical and radiological improvements. Presence and degree of spondylolisthesis, presence of intra-articular facet effusion, age of the patient and height of the cage were predictive factors of major clinical improvements.</p></sec>